Iran confirmed that some companies at European airports were refusing to sell it fuel, and its flag carrier said planes were making unscheduled stops en route to Tehran because they could not refuel in London.Iran has played down the impact of international sanctions over Iran's nuclear programs, which were tightened in June, and previously dismissed reports that Iranian airlines were having problems refueling abroad as part of a psychological war.Iran has been hit by a new wave of international sanctions over its nuclear enrichment activities. The measures have reduced the number of suppliers willing to sell the country gasoline and have made international financial transactions more difficult to reach.The United States and its European allies fear Iran is trying to build a bomb under cover of a civilian nuclear program. Iran says it needs nuclear technology to generate power and is not seeking atomic weapons.The imposed sanctions against civil-aviation are disputable, especially as they have had more impact on ordinary civilians causing non-necessary stops in alternative airports such as Athens and Belgrade, or completely abandoning some destinations.